The BCR320U/BCR321U provides a low-cost solution for driving 0.5 W LEDs with a typical LED current of 100 mA to 250 mA. The internal breakdown voltage of these devices is 24 V. This is the maximum voltage that the LED driver IC can sustain when connected to an LED directly. The BCR420U/ BCR421U has an internal breakdown voltage of 40 V and can supply an LED current of 50 mA to 150 mA. All of these LED drivers can be operated at supply voltages above 24 V or 40 V, respectively, by simply stacking a series of LEDs in front of the IC. This results in a certain voltage drop depending on the forward voltages of the LEDs and reduces the voltage at the supply pin of the driver below 24 V/40 V. Also, a digital input pin (on the BCR321U and BCR421U only) allows dimming via a Microcontroller with frequencies of up to 10 kHz. Additionally, a reduction of the output current at higher temperatures is the result of the negative thermal coefficient of 0.2%/K. of the LED drivers.